Fine Simulation Of Tropical Cyclone Boundary Layer Wind Field And Its Wind Engineering Parameter Characteristics Under Different Costal Topographies

China is affected by tropical cyclones(TCs) frequently. The high wind caused by TCs must be taken into consideration for wind-resistance design in coastal areas. Understanding of TC boundary layer wind structure change and related wind engineering parameter characteristics under different costal topographies has a great significance for meteorological disaster prevention and reduction.According to the requirements of wind-resistance design, which consider influences of TCs in a certain probability or extreme intensity, TC intensity control technology and topography transformation technique were developed to build a fine predictive model base on the mesoscale numerical model WRF(Weather Research Forecast). It is demonstrated that the model can match the model terrain with any target TCs in different hitting directions and intensities, providing accurate simulations for a target TC over complex topography.Based on model experiment outputs, the wind engineering characteristics of TC cases with once in a century and extreme intensities are analyzed. Results indicate that the disaster-caused wind engineering parameters are most remarkable in the areas of the rain bands, the complex topographies, and the core range of TC particularly, which indicate the distribution of high wind and its abrupt change in TC efficiently. On this basis, wind regime of the sea-crossing project of Qiongzhou Strait project under TC’s effect was estimated. It is found that the catastrophability of TC not only relates to its intensity, but also the relative position to the bridge.Finally, this study takes typhoon Meranti(1010) as an example to investigate the effects of Taiwan Strait topography on TCs’ structure change and its wind engineering parameter characteristics. Results show that when moving northward into Taiwan Strait, two mesoscale vortexes occurred in the Strait, resulting in disturbance wave trains related to TC due to the shunting and leeward slope effects of Taiwan topography. The mesoscale systems can make cumulus convection promoted by strengthening the upward transport of heat and moisture, resulting in abnormal wind distribution. Thus the wind engineering characteristics associated with Meranti changed when it entering the Taiwan Strait.